The present invention is directed to a skylight with a sash mounted on the casement by means of spring-loaded carrier arms which are jointed and are mounted on one end on a hinged bearing attached to the top of the casement, and, on the other end, roughly in the middle of the sash, to a pivot bearing on the side beam of the sash, and the sash has a spindle between the pivot bearing and its upper edge on each side rail that interacts with a runner that is U-shaped in cross section and is placed on the side pin of the casement; and wherein the rail's cover plate adjacent the sash and bordering a groove overlaps the spindles when the sash is in the swinging position and, when the sash is in the closed position and the swinging position, the spindle is outside the working range of the cover plate, and, wherein, after activating a handle attached to the cross member of the sash when the sash is opened and the carrier arm is coupled with the sash, the sash tilts on the hinged bearing and, when opened with the sash uncoupled from the carrier arms, the spindles move in the rail groove toward the lower edge of the casement and the pivot bearing on the sash side of the casement comes off and the sash swings open.
In such a skylight, known from German Offenlegungschnift 2 708 785, there is the option of the sash being in the hinged setting or the swinging setting when opened. To make hinged opening possible, the sash is coupled to the carrier arms so that the sash moves synchronously with the carrier arms attached to it on the hinged axis formed by hinged bearings at the top of the casement. The spindles, which are attached to the sash permanently, describe a circular arc on the hinged axis. The runner on the casement side has a recess at its upper end so that the spindles can move in and out of the runner. As a result of this recess, the cover plate and hence the runner groove end before the area where the spindles tilt.
If the sashes are swung open after the sash and the carrier arm are uncoupled, the spindle remains unchanged near the recess on the runner and thus in front of the groove opening. Now when it is opened in the swinging position, no information of any kind is transmitted to the spindle so that there is a risk that the spindles will come off the runner again through the recess and not go through the grove opening into the groove itself and slide down in it, as is necessary to make the sash swing open. In order to limit the risk of improper adjustment when the sash is being opened, the runner has a molded spring pin which should counteract the holding force that makes the spindle come off the runner when the sash is swung open. However, there is a conflict for the holding force since, on the one hand, it must let the spindle move on and off the runner when the sash is moving on its hinges, but, on the other hand, it must keep it from coming off when the sash is supposed to swing open. Thus, for example, depending on the arrangement and design of the weight-balancing device on the sash, forces can act on the sash when it is opened that tend to lift the top of the sash off the casement and then also overcome the resistance exerted by the spring pin, whereupon the sash opens wrong and hangs uncontrolled by the pivot bearing on the carrier arm side.
The task of the invention is to make the desired method of opening the sash on a conventional skylight more reliable.